"I want to thank the Arms Control Association … for being such effective advocates for sensible policies to stem the proliferation of weapons of mass destruction, and most importantly, reduce the risk of nuclear war."

– Joseph Biden, Jr.
January 28, 2004
The Role of Nuclear Weapons: Japan, the U.S., and “Sole Purpose”

By Masa Takubo

On September 22, a day before President Barack Obama met with Japanese Prime Minister Yukio Hatoyama in New York, 13 nongovernmental U.S. security experts released an open letter calling on the two leaders “to support a U.S. policy declaring that the only purpose of nuclear weapons is to deter, and if necessary respond to, the use of nuclear weapons by other countries.”[1]

The letter was prompted in part by the coincidence of two events: the U.S. Nuclear Posture Review (NPR), which is supposed to be completed by December and delivered to Congress shortly after, and the victory of the Democratic Party of Japan (DPJ) in August. The nuclear policies of the DPJ appear to be markedly different from those of its predecessor, the Liberal Democratic Party, which dominated Japanese politics for more than 50 years.

A key element of the Japanese-U.S. security relationship has been the U.S. pledge to protect Japan against any attack. That pledge has been understood by the Japanese government as an offer of a “nuclear umbrella,” or extended nuclear deterrence, covering attacks on Japan with conventional, chemical, or biological weapons, as well as nuclear weapons.

The security experts’ letter called for a policy of limiting the role of nuclear weapons to deterrence of only nuclear attacks.[2] The letter explained:

This policy would be consistent with President Obama’s [April 5] statement in Prague that he will reduce the role of nuclear weapons in U.S. national security strategy, and urge other countries to do the same.

Such a change in U.S. policy will also strengthen the Nuclear Non-Proliferation Treaty—a goal of both nations—by reinforcing the negative security assurances the nuclear weapons states have made not to use nuclear weapons against states without nuclear weapons. It will also reduce the incentive for more countries to acquire nuclear weapons.[3]

The current Japanese-U.S. arrangement has come to function as a barrier to global nuclear nonproliferation and disarmament. Because of a fear in the United States and elsewhere of the perceived prospect that Japan might acquire its own nuclear arsenal if it came to regard the nuclear umbrella as unreliable, the arrangement in effect gives Japan significant leverage. It allows Japan to put pressure on the United States to avoid taking any significant steps to reduce the salience of nuclear weapons in its security and military doctrines and thus impedes progress on freeing the world of nuclear weapons. Those in the United States who oppose narrowing the role of nuclear weapons could also use Japan’s position as an excuse for not changing the current U.S. policy.

Former Secretary of Defense William Perry, one of the four authors of Wall Street Journal op-eds calling for a world free of nuclear weapons, said in a recent meeting in Tokyo that he has also been calling on Obama to adopt a policy declaring that the “sole purpose” of U.S. nuclear weapons is to deter the use of such weapons by others.[4] He said this “sole purpose” declaration would amount to a no-first-use declaration but that the latter is not acceptable in the United States because the concept is tarnished by its abuse during the Cold War, when the Soviet Union advocated no-first-use while, as was later discovered, it was preparing for first use.[5] Thus, in discussions today, the sole purpose, or “only purpose,” declaration is usually interpreted as a euphemistic substitute for a no-first-use declaration.[6]

Katsuya Okada, Japan’s new foreign minister, has been a staunch advocate of no-first-use, but bureaucrats in his ministry are resisting that idea and the sole purpose concept. According to the security experts’ letter and other accounts, these Japanese skeptics are playing an important role in the U.S. NPR. The letter said that “[s]ome Japanese bureaucrats want to preserve the status quo, and argue that such a change in U.S. nuclear policy could undermine Japan’s confidence in U.S. security guarantees.”[7] It warned that some Americans “remain mired in Cold War thinking, and cite these Japanese concerns to argue against changing U.S. policy, which they contend could lead Japan to build its own nuclear weapons.”[8]

In an October 18 speech in Kyoto, Okada noted the central contradiction in Japanese policy on nuclear weapons: “Hitherto, the Japanese government has said to the U.S., ‘We don’t want you to declare no first use because it will weaken nuclear deterrence.’ However, it cannot be said to be consistent to call for nuclear abolition, while requesting the first use of nuclear weapons for yourself.”[9]

The International Commission on Nuclear Non-proliferation and Disarmament (ICNND), co-chaired by former Foreign Ministers Yoriko Kawaguchi of Japan and Gareth Evans of Australia, is scheduled to issue its report in the coming months. Referring to the ICNND, which was meeting in Hiroshima the same day he spoke in Kyoto, Okada said, “As a general course, we should discuss what could be done to achieve no first use of nuclear weapons. I would expect that the Evans-Kawaguchi report would be along those lines. When the report comes out, I would like to discuss this no-first-use issue fully with the United States."[10]

Historical Background[11]

Why do some believe that Japan will seek a nuclear capability if the United States adopts a sole purpose policy? After all, Japan takes pride in having adopted three non-nuclear principles. Formalized in 1967 by Prime Minister Eisaku Sato, they specify a clear commitment not to possess or produce nuclear weapons or to permit their entry into the country.[12] Japan is a strong supporter of the nuclear Nonproliferation Treaty (NPT) and the lead sponsor of a widely supported UN General Assembly resolution on nuclear disarmament that has been adopted every year since 1994.[13]

The answer lies in the history of Japan’s nuclear policy. When Japan adopted its three non-nuclear principles, it was, in Sato’s mind, part of a package in which protection by the nuclear umbrella of U.S. extended deterrence was a precondition.[14] The implication is that Japan will not seek nuclear weapons as long as the nuclear umbrella is regarded as reliable.

Sato raised the issue of the nuclear umbrella during a conversation with Secretary of Defense Robert McNamara on January 13, 1965. According to a summary, Sato said, “Please be careful about statements concerning bringing nuclear weapons onto the land. Of course, should a war break out, it would be a different story. We expect that the U.S. will immediately retaliate with nuclear weapons.”[15] These comments were made shortly after China’s first nuclear test, which took place on October 16, 1964.

In 1982 the Japanese government officially expressed its view that the U.S. nuclear umbrella provides for a first-use option in retaliation for an attack by conventional weapons. This explanation was given in response to a question raised by Diet member Takahiro Yokomichi on February 19, 1982, concerning a statement made the previous year by Eugene Rostow, director of the U.S. Arms Control and Disarmament Agency. Rostow had said that, as with its extended deterrence policy for Western Europe, the United States would be prepared to use nuclear weapons if the Soviet Union attacked Japan with conventional weapons.[16] On June 25, 1982, a government official told the Diet that this understanding was implied in a 1975 press statement issued jointly by President Gerald Ford and Prime Minister Takeo Miki.[17] Referring to the joint statement, the official said, “We believe that in the sense that all the measures are included, it would mean that the nuclear deterrent or retaliation would not be limited to nuclear attacks against Japan.”[18]

Later, with the Cold War between the United States and the Soviet Union over, government officials and security experts in Japan started to consider the security implications of North Korea’s chemical and biological weapons, as well as China’s conventional weapons buildup. In 2003, for example, the Yomiuri Shimbun reported that Mitoji Yabunaka, director-general of the Foreign Ministry’s Asian and Oceanian Affairs Bureau, filed a request with Assistant Secretary of State for East Asian and Pacific Affairs James Kelly “to make sure the United States does not again [as in 1994] promise not to use its nuclear weapons against North Korea if Pyongyang agrees to dismantle its nuclear development program.”[19]

More recently, when asked about encouraging the United States to adopt a no-first-use policy, Prime Minister Taro Aso told an August 9 press conference in Nagasaki that, “[i]n international society, there exist large arsenals including nuclear forces…. It could disturb the deterrence balance and undermine security to have a discussion separating nuclear weapons from other weapons.”[20] Reiterating what Masahiko Komura had said when foreign minister in 1999, Aso said, “Even if a nuclear power says it won’t make a pre-emptive strike, there’s no way to verify its intentions. I wonder if that’s a realistic way to ensure Japan’s safety.”[21]

Such assertions about the difficulty of verifying a no-first-use declaration might have been referring to China, which has maintained a no-first-use policy since 1964. That policy is often considered a piece of propaganda in Japan. The Japanese responses cited above intentionally or unintentionally confuse the no-first-use policies of an adversary, China, and those of an ally, the United States. Aso’s remarks were made in response to a question about U.S. policy, in the context of the United States perhaps being able to make a contribution to the efforts toward global nuclear disarmament by declaring a no-first-use policy. This declaration could reduce international tension and the role and value of nuclear weapons and perhaps prepare the way for further reductions in the number of nuclear weapons.

Japan is also said to be actively trying to influence other aspects of U.S. nuclear policy. In his Web log discussing nuclear-tipped Tomahawk land attack missiles (TLAM/N), Hans M. Kristensen of the Federation of American Scientists points out that Japan is being cited as the main reason for the potential life extension of the TLAM/N force, which has been virtually retired since the days of President George H. W. Bush.[22] The 2009 final report of the Congressional Commission on the Strategic Posture of the United States, headed by Perry and James Schlesinger, says:

In Asia, extended deterrence relies heavily on the deployment of nuclear cruise missiles on some Los Angeles[-]class attack submarines – the Tomahawk Land Attack Missile/Nuclear (TLAM/N). This capability will be retired in 2013 unless steps are taken to maintain it. U.S. allies in Asia are not integrated in the same way [as NATO countries] into nuclear planning and have not been asked to make commitments to delivery systems. In our work as a Commission it has become clear to us that some U.S. allies in Asia would be very concerned by TLAM/N retirement.[23]

In testimony to the House Armed Services Committee May 6, Schlesinger said Japan “is the country that has perhaps the greatest leaning, amongst the 30-odd nations that we have under the umbrella, to create its own nuclear force, and therefore, intimate discussions with the Japanese, I think, are mandatory at this stage.”[24] Perry followed Schlesinger by saying that even if the United States does not see the need to deploy certain weapons, it should take into consideration the concerns of its allies. He said there still is “great concern in both Europe and in Asia about the credibility of our extended deterrence…. It is important for us to pay attention to their concern and not try to judge whether deterrence is effective by our standard, but we have to take their standards into account as well. And a failure to do this…would be that those nations would feel that they had to provide their own deterrence. They would have to build their own nuclear weapons.”[25]

The position of past Japanese administrations has influenced the deliberations of the ICNND, although the commission is an independent body. In addition to commission co-chair Kawaguchi, the advisory board has three Japanese members. Two are former high-ranking officials of the Ministry of Foreign Affairs who are strongly opposed to the idea of limiting the role of nuclear weapons to the sole purpose of deterring nuclear attacks, let alone a no-first-use declaration by the United States. The third adviser is the chair of the Japanese Atomic Energy Commission, who was presumably chosen in part to protect another aspect of Japan’s nuclear policy: Japan’s right to uranium enrichment and spent fuel reprocessing.

When Evans came to Japan in May, he warned that Japan’s position on the need for the nuclear umbrella against conventional, chemical, and biological weapons was a major obstacle to the commission's approval of a recommendation to call on the United States to adopt a no-first-use policy.[26]

The Australian newspaper The Age reported September 4 that although “most of the 15-member commission, including Australia's co-chairman, former foreign minister Gareth Evans, plan to call on nuclear-armed states to change their defence doctrine and declare they will only use atomic weapons when faced with direct nuclear attack,” Kawaguchi opposed the idea.[27]

Later that month, Japan’s Kyodo News said the Japanese team opposed language in the draft report calling for U.S. statements on nuclear doctrine before the May 2010 NPT Review Conference. According to the article, the draft report said the ''sole purpose of U.S. nuclear weapons is to deter use of nuclear weapons against the United States and its allies and (possibly) that the United States is willing to consider moving in combination with other nuclear armed states to a clear no-first-use posture.”[28]

Overestimated Threat

How strong are Japan’s objections to U.S. adoption of a new policy on the role of nuclear weapons and deeper nuclear weapons reductions? Is it actually likely that if the United States adopted such a policy, Japan would violate its NPT obligations and seek to acquire nuclear weapons against the wishes of the United States and world opinion? There is a big difference between a theoretical possibility and a realistic probability that Japan will go nuclear. Also, a U.S. no-first-use policy does not imply the cessation of Japanese-U.S. security arrangements or a withdrawal of the U.S. nuclear umbrella against possible nuclear attacks. Furthermore, a Japanese nuclear-weapon program could in fact jeopardize Japan’s security arrangement with the United States and its position in the international community. Former Minister of Defense Shigeru Ishiba, who is known for his knowledge of nuclear and military affairs, recently said about Japan exercising the option to develop nuclear weapons, “That would naturally mean Japan withdrawing from the NPT. We would not be able to obtain nuclear fuel.... With dependency on nuclear power for about 40% of [our] electricity, we would experience a major decline in economic activities. Japan going nuclear would automatically mean the collapse of the NPT regime and there would be nuclear countries all around us.”[29] In a book published three years ago, Ishiba said, “In any case, the voters would not allow such a thing as possession of nuclear weapons.”[30] Japan would have to consider these realities before going nuclear, which so-called realists in the United States tend to ignore. Ishiba, a conservative, knows about these realities. If the United States adopts a sole purpose policy, can one really argue that Japan would believe that whatever benefits it might gain from going nuclear would outweigh the negative consequences?

The DPJ, which won a landslide victory in Japan’s August 30 election, declared its nuclear policy supporting no-first-use in 2000. Okada was the head of the team that developed this policy. Although the current official status of the document is not clear, on May 12, 2009, Okada, who was DPJ secretary-general at the time, told a Diet session that “a norm not allowing at least first use, or making it illegal to use nuclear weapons against countries not possessing nuclear weapons, should be established. Japan should be at the forefront of this effort as a leader.”[31] In an interview soon after, Okada elaborated on his position:

I believe that Japan should advocate the following three points: that the states possessing nuclear weapons, the United States in particular, should declare no first use; formation of an agreement that it is illegal to use nuclear weapons against countries without nuclear weapons; and, partly overlapping with these two, the initiative of a Northeast Asian Nuclear-Weapon-Free Zone.

If the United States declares no first use, that does not mean that Japan will be completely outside the nuclear umbrella. In a situation where nuclear weapons actually exist in this world, it would be natural that people feel worried about the nuclear umbrella going away.

I talk about going out of the nuclear umbrella halfway, where first use would not be exercised, but in the unfortunate case that Japan suffers a nuclear attack, we are not ruling out a nuclear response to it. We have such an assurance ultimately. So please understand that I am not just talking about an idealistic theory.[32]

He said, however, that “[w]e do not necessarily need a nuclear umbrella against the nuclear threat of North Korea. I think conventional weapons are enough to deal with it.”[33]

At the recent Tokyo meeting, Perry said that the combined conventional forces of Japan and the United States would be enough to deter nuclear attacks of North Korea and that those forces could cause devastating damage. North Korea’s leaders know that, and they are not suicidal, he said.[34]

Okada repeated his position in the inaugural Cabinet press conference on September 16, saying, “My own personal belief has been to question whether countries which declare their willingness to make first use of nuclear weapons have any right to speak about nuclear disarmament, or nuclear nonproliferation, in particular nonproliferation.”[35]

During an October 20 meeting in Japan with Secretary of Defense Robert Gates, Okada told Gates that the Japanese government currently is examining the no-first-use issue and that he would like to discuss it with the United States. Gates responded that the flexibility of deterrence is necessary.[36] Three days later, Chairman of the Joint Chiefs of Staff Adm. Mike Mullen expressed his agreement with Gates while in Tokyo.[37] Thus, U.S. defense officials appear to be resisting adoption of a new policy advocated by a Japanese foreign minister, rather than the other way around.

Okada also has taken steps to investigate secret understandings between Japan and the United States, which include those related to the third non-nuclear principle of not permitting nuclear weapons to enter Japan.[38] The United States and Japan have not strictly adhered to this principle. Documents declassified in the United States show a secret agreement at the time of the 1960 revision of the Japanese-U.S. security treaty to allow port calls by U.S. ships carrying nuclear weapons.[39] On September 17, Okada ordered the Foreign Ministry’s top bureaucrat to investigate the issue of secret pacts. Because of the 1991 decision by Bush to withdraw nuclear weapons from surface ships and attack submarines, the port-call issue has been moot. Yet, the alleged request by Japan to put TLAM/N on attack submarines, which frequently stop at Japanese ports, would, if realized, lead to a situation necessitating secret pacts or abandonment of the third principle. The logical step for Okada is to investigate these “requests” and withdraw them officially if Japan is to come clean and keep the third principle intact. It would be rather difficult for Japan to tell the United States not to bring in any nuclear weapons, while demanding that the United States put tactical weapons on attack submarines that roam around Japan and keep open the option of using nuclear weapons in response to a non-nuclear attack on Japan.

The picture should be clear to Obama. Okada’s speech in Kyoto and his explanation to Gates about the policy review taking place within the Japanese government should be interpreted as a message to the Obama administration to act boldly in its NPR process and adopt a sole purpose policy, if not a no-first-use policy.


The Guardian reported September 20 that Obama rejected a draft NPR because it was too timid. According to the report, Obama called for a range of more far-reaching options, including more radical reductions of nuclear weapons and a redrafting of nuclear doctrine to narrow the range of conditions under which the United States would use nuclear weapons.[40] In his September 23 speech to the UN General Assembly, Obama appeared to provide a hint of his intentions when he said: “We will complete a Nuclear Posture Review that opens the door to deeper cuts and reduces the role of nuclear weapons.”[41]

The ICNND is expected to release its final report in a weakened form around January 2010.[42] The Japanese government should not wait until then to express its official support for a sole purpose policy. Japan also should encourage the United States to declare a clear no-first-use policy. However, Obama should not wait for Japanese action to make bold changes in U.S. nuclear policy.

The world now has an opportunity to make significant steps toward a nuclear-weapon-free world. Outdated and misunderstood policies should not stand in the way.

Masa Takubo is an independent analyst on nuclear issues living in Japan and operator of the nuclear information Web site Kakujoho. This article is based in part on a chapter on Japan’s attitudes toward nuclear disarmament in a forthcoming report by the International Panel on Fissile Materials.


Unless otherwise noted, all translations are the author’s.

1. Union of Concerned Scientists, “Letter Urges Obama, Hatoyama to Change Nuclear Policy,” September 22, 2009, www.ucsusa.org/news/press_release/letter-urges-us-japan-nuclear-0285.html (hereinafter Union of Concerned Scientists letter).

2. This would mean adoption of “core deterrence,” defined by the U.S. National Academy of Sciences’ Committee on International Security and Arms Control as “the restricted form of extended nuclear deterrence in which coverage is intended against nuclear threats—and only nuclear threats—to one’s own country and to one’s allies.” See Committee on International Security and Arms Control, National Academy of Sciences, “The Future of U.S. Nuclear Weapons Policy,” 1997, p.15, www.puaf.umd.edu/Fetter/1997-fun.pdf.

3. Union of Concerned Scientists letter.

4. William Perry, Remarks at “The Japan-US Partnership Toward A World Free of Nuclear Weapons,” Tokyo, October 21, 2009 (hereinafter Perry remarks).

5. Ibid.

6. Some Cold War thinkers could interpret “sole purpose” to allow for a scenario for first use: a counterforce first strike for the purpose of limiting the damage when the enemy is considered to be about to attack with nuclear weapons. Therefore it will eventually be necessary to rule out this scenario by making a clear-cut no-first-use declaration. See Hans M. Kristensen, Robert S. Norris, and Ivan Oelrich, “From Counterforce to Minimal Deterrence: A New Nuclear Policy on the Path Toward Eliminating Nuclear Weapons,” Occasional Paper No. 7, Federation of American Scientists and Natural Resources Defense Council, April 2009.

7. Union of Concerned Scientists letter.

8. Ibid.

9. Katsuya Okada, Remarks at “Atarashii Jidai no Nichibei Kankei” [Japan-U.S. relationship in a new era], Kyoto, October 18, 2009.

10. Ibid.

11. For more information, see Masa Takubo, “Japan's Challenges and Dilemmas Over Nuclear Disarmament,” Disarmament Diplomacy, No. 91 (Summer 2009).

12. The policy of the three non-nuclear principles was first expressed by Prime Minister Eisaku Sato at the Diet (House of Representatives Budget Committee) on December 11, 1967. See Kokuritsu Kokkai Toshokan [National Diet Library], Shugiin Kaigiroku Joho [House of Representatives minutes], December 11, 1967, http://kokkai.ndl.go.jp/SENTAKU/syugiin/057/0514/05712110514002a.html.

13. See Japanese Ministry of Foreign Affairs, “Adoption of Nuclear Disarmament Resolution Submitted by Japan to the 63rd Plenary Session of the United Nations General Assembly,” December 3, 2008, www.mofa.go.jp/announce/announce/2008/12/1185313_1080.html; UN General Assembly, “Australia, Austria, Bangladesh, Belgium, Canada, Chile, Czech Republic, Dominican Republic, El Salvador, Finland, Germany, Italy, Japan, Liechtenstein, Lithuania, Luxembourg, Paraguay, Philippines, Switzerland, the former Yugoslav Republic of Macedonia and Ukraine: Draft Resolution: Renewed Determination Towards the Total Elimination of Nuclear Weapons,” A/C.1/63/L.58, October 23, 2008, www.mofa.go.jp/policy/un/disarmament/arms/un0810.pdf.

14. Sato explained the relationship between the nuclear umbrella and the principles as follows: “What should Japan do about its security under the three principles concerning nuclear weapons: not possessing, not producing, and not bringing in nuclear weapons?… When I met President Johnson last time in 1965, and this time too, I said: ‘Could the Japan-U.S. security treaty defend Japan against any kind of attacks?’ In other words, is it useful against nuclear attacks? President Johnson said [that the U.S.] will clearly defend Japan against any attacks.” House of Representatives Budget Committee, December 11, 1967. See Kokuritsu Kokkai Toshokan [National Diet Library], Shugiin Kaigiroku Joho [House of Representatives minutes], December 11, 1967, http://kokkai.ndl.go.jp/SENTAKU/syugiin/057/0514/05712110514002a.html.

15. “Sato Makunamara Kaidan no Omona Yaritori” [Main conversation at the Sato-McNamara meeting], Kyodo News, December 22, 2008, http://yamagata-np.jp/news_core/index_pr.php?kate=Detail&no=2008122101000153&keyword=. The summary was among the documents declassified last December by the Ministry of Foreign Affairs.

16. House of Representataives Budget Committee, February 19, 1982. See Kokuritsu Kokkai Toshokan [National Diet Library], Shugiin Kaigiroku Joho [House of Representatives minutes], February 19, 1982, http://kokkai.ndl.go.jp/SENTAKU/syugiin/096/0380/09602190380013a.html.

17. “Further, they recognized that the US nuclear deterrent is an important contributor to the security of Japan. In this connection, the President reassured the Prime Minister that the United States would continue to abide by its defense commitment to Japan under the Treaty of Mutual Cooperation and Security in the event of armed attack against Japan, whether by nuclear or conventional forces.” For the full statement, see “Japan-U.S. Joint Announcement to the Press (by Prime Minister Takeo Miki and President Gerald R. Ford),” Washington, August 6, 1975, www.ioc.u-tokyo.ac.jp/~worldjpn/documents/texts/JPUS/19750806.O1E.html (hereinafter Miki-Ford statement).

18. House of Representatives Budget Committee, June 25, 1982. See Kokuritsu Kokkai Toshokan [National Diet Library], Shugiin Kaigiroku Joho [House of Representatives Minutes], June 25, 1982, http://kokkai.ndl.go.jp/SENTAKU/syugiin/096/0380/09606250380022a.html.

19. “Govt Wants U.S. to Keep North Korea N-Deterrent,” Daily Yomiuri, August 23, 2003.

20. “Shusho Kaku Senseifushiyo niwa Hiteiteki” [Prime minister negative about no first use], Nihon Hoso Kyokai [Japan Broadcasting Corporation], August 9, 2009.

21. Ibid.

22. Hans Kristensen, “Japan, TLAM/N, and Extended Deterrence,” FAS Strategic Security Web log, July 2, 2009, www.fas.org/blog/ssp/2009/07/tlam.php. See Jeffrey Lewis, "Japan ♥ TLAM/N,” ArmsControlWonk Web log, May 8, 2009, www.armscontrolwonk.com/2284/japan-tlamn.

23. Congressional Commission on the Strategic Posture of the United States, “America’s Strategic Posture,” 2009, p. 26, http://media.usip.org/reports/strat_posture_report.pdf. The commission’s wording in this passage could be read to suggest that TLAM/N are currently deployed on the Los Angeles-class submarines. As discussed elsewhere in this article, that is not the case.

24. James Schlesinger, Statement before the House Armed Services Committee, May 6, 2009, http://armedservices.house.gov/hearing_information-jan-may2009.shtml.

25. William J. Perry, Statement before the House Armed Services Committee, May 6, 2009, http://armedservices.house.gov/hearing_information-jan-may2009.shtml.

26. Yumi Kanazaki,“Kakuno Kasa Kaishaku Saikowo” [Interpretation of nuclear umbrella should be reexamined], Chugoku Shimbun, May 28, 2009.

27. Daniel Flitton, “Australia, Japan in Nuclear Rift,” The Age, September 4, 2009, www.theage.com.au/national/australia-japan-in-nuclear-rift-20090903-f9yw.html.

28. “Japan Reluctant to Accept Proposal for U.S. to Reduce Role of Nukes,” Kyodo News, September 13, 2009, www.breitbart.com/article.php?id=D9AMDKV80&show_article=1.

29. Shigeru Ishiba and Kazuhisa Ogawa, Nhihon no Senso to Heiwa [Japan’s war and peace] (Tokyo: Bijinesu Sha, 2009), p. 284.

30. Shigeru Ishiba and Shinichi Kiyotani, Gunjiwo Shirazushite Heiwa wo Kataruna [Without knowing military affairs, do not talk about peace] (Tokyo: KK Best Sellers, 2006), p. 176.

31. House of Representatives Budget Committee, May 12, 2009. See Kokuritsu Kokkai Toshokan [National Diet Library], Shugiin Kaigiroku Joho [House of Representatives minutes], May 12, 2009, http://kokkai.ndl.go.jp/SENTAKU/syugiin/171/0018/17105120018027a.html. LDP member Taro Kono argued in the Diet in 1999 for a Japanese-U.S. joint declaration for no-first-use. House of Representatives Foreign Affairs Committee, June 12, 1999). See Kokuritsu Kokkai Toshokan [National Diet Library], Shugiin Kaigiroku Joho [House of Representatives minutes], June 12, 1999, http://kokkai.ndl.go.jp/SENTAKU/syugiin/145/0005/14506020005008c.html.

32. Katsuya Okada, “Interview: Ajia no Naka no Nihon toshite Anzen Hosho Seiseku wo Kochiku Shinakereba Naranai” [We should develop a security policy as Japan inside Asia], Sekai, July 2009, pp. 138-143.

33. Ibid.

34. Perry remarks. He also emphasized the importance of nonmilitary deterrence, including economic power.

35. Katsuya Okada, Remarks at ministers’ inaugural press conference, September 16, 2009. See Seifu Intanet Terevi [Government Internet TV], “Daijin Shunin Kaiken” [Ministers' inaugural press conference], September 16, 2009, http://nettv.gov-online.go.jp/prg/prg2758.html.

36. Japanese Ministry of Foreign Affairs, “Press Conference by the Deputy Press Secretary (English),” October 22, 2009, www.mofa.go.jp/announce/press/2009/10/1022.html.

37. “Top U.S. Military Officer Warns Japan Against Reneging on Futemma Plan,” Kyodo News, October 23, 2009, www.breitbart.com/article.php?id=D9BGR3R84&show_article=1.

38. Tomoko A. Hosaka, “Japan launches probe of secret pacts with US,” Associated Press, September 24, 2009, www.sfgate.com/cgi-bin/article.cgi?f=/n/a/2009/09/24/international/i224839D04.DTL&feed=rss.business.

39. For related declassified documents, see www.gwu.edu/~nsarchiv/nukevault/ebb291/index.htm.

40. Julian Borger, “Barack Obama Ready to Slash US Nuclear Arsenal,” The Guardian, September 20, 2009, www.guardian.co.uk/world/2009/sep/20/barack-obama-us-nuclear-weapons.

41. Office of the Press Secretary, The White House, “Remarks by the President to the United Nations General Assembly,” United Nations headquarters, New York, September 23, 2009, www.whitehouse.gov.

42. “International Panel Calls for Nuke Disarmament After 2025 at Conference in Hiroshima,” Mainichi Daily News, October 21, 2009, http://mdn.mainichi.jp/mdnnews/news/20091021p2a00m0na016000c.html.